So, what is this so called map seed? It is a random value. Unfortunately it is slightly misnamed as *map* seed. It would probably be much better to call it game seed. A "seed" is a random value used by a game's (or other program on a computer) random number generator. Basically computers work for creating random values by using a formula that take some value (usually called seed) and then spit out a new value (a new seed). Those values are more or less "random". That is, for somoene just lookiing at the resulting random value, there is no real way to predicty the next one. Also, all results for the random value is equal probable and the distribution is good (that is, it is not 1, 2, 3 , 4 and so on). Obviously one need a starting value for this (that is the first seed). It should be one that is as random as possible and vary each time you start a new game (for example). The first seed, the starting value for the random number generator, is called "map seed" and it is just the intial seed generated from the computers clock and the time it has been turned on. That is, the starting value for the random number generator and it is saved with your character. Since the random number generator works by applying a specific formula to a seed value and then generate the next value from the previous one and so on, as long as you don't change the difficulty setting in single player, you will get an exact same order of random values. If you use those values to generate a map for example, you will get an identical map if the starting seed was identical. Now, as you play, something will not happen in the exact same order, like monster killed and so on which makes the seed to be used for a particular item, to NOT be the same each time you kill for example the "same" monster. The item type is determined by the monsters current seed for example, since EVERY action the monster do basically needs a random number or more, it will hardly ever be the same (just making an attack for example requires several random rolls, as do simple movement or starting an action). Even if the seed for the rest of the item creation is the same, a change in item type will give a completely different result. Now, for chests, racks and such, there is not much they do in the game, they just sit there and then pop out item(s). They should have their own seed set to them (since they are units as is basically everything in the game). Their seed values seem to be effected by the room seed: as you move on alternate routes in an area, the game generates the various sub sections of the map in a slightly different order and only near your character, that's how it is possible that taking different routes to a rack with a fixed location results in different item drops. If you move in different directions at a certain location, the room seed may have to generate different monsters, so the random number generator spits out different room seed values. Eventually, the seed value of the racks in the room will be derieved from the room seed, and this difference in the room seed caused by moving on alternate routes and forcing the game to generate different monsters will lead to different rack drops. However, pre-1.09, the monster seeds do not(?) effect the room seed - it was changed in a later patch so that all the units with seeds in the room are initialized - so killing them does not effect your rack drops as long as you do not move too much while killing so that you do not force the game to spawn more monsters. The only other factor other than the alternate routes that effects the room seed (thus the rack drops) are other racks. If more than one rack exist in a room and you click on one of them, the others will drop totally different item types as if you hadn't clicked on it, since acting so made the random number generator spit out a new value, and the seed value of the next rack was then calculated of this latest seed value using a formula etc.
